The prostate is a small gland about the size and shape of a chestnut. It is situated just below the bladder and surrounds the urethra, the passage that carries urine from the bladder through the penis during urination.

Women do not have a prostate.

The prostate secretes fluid, which forms part of the semen in which sperm are transported. During sexual activity and orgasm, the semen enters the urethra and passes along it through the penis to the outside. This is called ejaculation.